Like another poster I live a few minutes flying time from LHR-on Saturday there was quite heavy (for UK) snow falling but not settling. To be fair to LHR wet snow is a pain to deal with but unlike its Scandi/Canadian/US heavy snowfalls we get a fair bit of that plus one to minus one weather and while its not economic to protect LHR against really heavy snow this sleety type weather is pretty common .
The problems for pax are that LHR operates right on the capacity margins with no room for adapting to problems
Not enough runway capcity , not enough aircraft parking, not enough de- icing . Terminals with not enough space as they are full of useless shops and so when something goes moderately wrong the whole place collapses in a house of cards manner.
The other issue is that BA now mirrors LHR- everything , except executive salaries, has been cut to the bone . Works, just, with a fair wind but as soon as anything goes wrong there are no staff to book flights no staff to book hotels, lounges outsourced to people who do not care about throwing F pax into the street , staff demotivated and treated like dirt so less inclined to overtime or helping.
BA is getting close to be Better Avoid once again under Sr Cruz , cannot blame him for the snow but the ensuing chaos and more specifically the lack of support staff to help people stranded miles from home , not feeding them because you outsourced short haul food , not getting long haul pax to hotels when they face 24 hour delays is all down to him.